Rubbing-machine.



G. H. EKSTROM.

RUBBING MACHINE.

APPLICATION FILED 0m22.191s.

I. ,U6 Patented Aug. 21, 1917.

aan stares natuur ernten.

GUSTAF H. EKSTBOM, OF ROCKFORD, ILLINOIS, ASSIGNOR, TO ROCKFORD -TOOL COM- PNY, 0F ROCJKFORD, ILLINOIS, A CORPORATION OF ILLINOIS.

RUBBING-IVIACHINE.

Specification of Letters Patent.

Patented Aug. 21, 191'?.

Application filed December 22, 1916. Serial No. 138,495.

4particularly to' portable machines of thisclass intended for use in rubbing and polishing the varnished surfaces of woodwork.

One of the objects of this invention is to produce a machine of the class described which shall be of suiiiciently small and compact construction to permit its use in rubbing and polishing the comparatively narrow depressed surfaces that occur in paneled woodwork.

Another object of the invention is to simplify and cheapen the construction while preserving a high degree of eiciency and durability.

In the accompanying drawings, Figure 1 is a view (largely in section) of a portable rubbing machine embodying the features of my invention. Fig. 2 is a vertical transverse sectional view taken in the .plane of dotted line 2 2 of Fig. 1. Fig. 3 is a fragmental transverse view on dotted line 3 3 of Fig. 1. Fig. 4 is a fragmental detail view.

The embodiment herein shown of this invention comprises a body 1, .a handle 2 rigidly secured to the body, a reciprocating structure supported by the body, and a rubbing pad secured to said reciprocating structure.

The body 1 is tubular and cylindrical, save that the lower side thereof is cut away as indicated in Figs. 2 and 3. The handle 2 is rigidly connected to the body midway ofthe length of the body and projects upwardly therefrom. Within the body 1 is a cylindrical tubular element 3 extending axially of the body. The inner endof the handle 2 is@ reduced in diameter and is y,screw-threaded to engage a screw-threaded body 1, the element 3 and the spacer plate 5 rigidly together.

A tube 6 fits slidably within the body 1 and surrounds the element 3. Said element its snugly within the tube. The plate 5 serves to prevent relative rotation between the body 1 and the tube 6. The tube has an elongated opening 7 therein to accommodate the spacer plate 5, the opening 7 being of sufficient length to allow reciprocation of the tube 6 within the body 1. The ends of the tube 6 are closed by means of heads 8 and 9 which are held in place by means of a rod or stem 10 extending axially of the tube 6, the ends of said rod being threaded to receive nuts 11. The opposite end portions /of the tube 6 constitute reciprocating power cylinders, the ends of the tubular element 3 serving as stationary pistons in said cylinders.

The middle portion 12 of the rod 10 is of greater diameter than the end portions of said rod, thus forming annular shoulders 13 and 14 on the rod. In the ends of the tubular element 3 are secured bushings 15 which are of less internal diameter than the tubular element 3, the inner ends of the bushings 15 thus forming annular shoulders 16 and 17 rlthe openings through the bushings 15 ,constitute ports through which pressure fluid Hows from the central chamber 3a ofthe tubular element to the cylinders.

VSuitable pressure fluid, as for example, coinpressed air,4 is admitted to the interior chamber 3a of the tubular element 3 by suitable means, as, for example, by providing a passage 18 extending axially of the handle 2. They outer end of the passage 18 is arranged to communicate with the source of' supply by means of a flexible tube (not shown U The portion 12 of the rod 10 1s of greater length than the distance between the shoulders 16 and 17. The rod 10 is adapted to lit snugly within the bushings 15.

It will be seen that the shoulders 13 `and -16 constitute coperating valves to control two sets of exhaust ports 19, one set 'for each'power cylinder. The end portions of the tubular element 3 constitute valves to.`

close communicationwith the atmosphere through the exhaust ports. l

' The rubbing or polishing element may be of any suitable or preferred construction.

- 'Herein is shown a bracket 20 havingperforated ears 21 through which thev rod-10 extends, said ears being clamped against the heads 8 and 9 by means ofthe nuts 11. The

bracket comprises 'a flange or web 22 to which a vblock 23 of woodor other suitable material is secured by meanssuch as bolts 24. Thel block 23 is provided with a rubber face 25. 26 isa strip of felt or other suit able friction material which is secured over the face by suitable means, as, forex- `Assuming the parts to be in the position ample, the nails 27 In the lower side of the body 1 `is a longitudinal slot v28 lthrough whichthe ears 21 move.

.. shown in Fig. 1, theoperation is as follows: Compressed air ows from the central cham'- berl 3a ofthe tubular element 3, past the annular shoulder 17 and along ,therod 10 tothe right-hand" ower Cylinder. The tube 6 is thereby cause to move toward the right.

l As soon as the shoulder 14 reaches the shoulder 17, the flow of air to the right-handcylinder is cut on', but the expanslon of the air contained in saidv cylinder causesl continuing movement of the tube 6. A moment before the shoulder 13 reaches the .shoulder 16, .one of the exhaust orts 19 passes the right-hand end of the tubular element 3, thus permitting` exhaust of the air rfrointhe right-hand cyl-v inder to commence. As soon as the shoulder 13 has passedfthe shoulder 16, compressed air flows from the central chamber 3a to the left hand cylinder, consequently as soon* as the momentum of the tube 6 can be overcome said ltube begins to move toward the left. l

The Asupply of compressed air to the lefthand cylinder is cut oif as soon as the shoulder 13. reaches the shoulderv 16 in theleft-l .the body hand movement of said cylinder.-v The tube is thus rapidly reciprocated, carrying with 1t the pad 26. The pressure of the'. air con-1 tained in the power cylinders preventsV the heads 8 and 9 from striking the ends ofthe tubular element. In practice the operator grasps l 2' and slides the machine over lthe' surface4 f be rubbed or polished. While .the machine. `1s being thus moved, the tube 6 and its atrubor polishthe'surface against. which the pad is pressed, suitable abrasive or polishing material bemg placedA upon said surface.

It will be evident that the machine herein v disclosed is of verysimple construction and comprises very few moving parts. I claim as my invention: l

l1. A portable-rubbing or'polishingmav' chine having, in combination, a body, a tube slidably supported by the body, the ends of the tube being closed, a vpiston-forming `element within thev tube and secured to thel body, said element having internal' annular shoulders near its ends, a rod; extending from end to end of the tube and through said element, the ends of said'rod being of reduced diameter' to provide two annular shoulders on the rod adapted 'tocoat with the shouli.` 'dersin-.the tubular element, the distance betweenthe .shoulderson the rod being greater lthan that between the shoulders in the tubui lar element, means .for admitting pressure v .v

fluid to the interior of the tubular element, exhaust means for the tube, and rubbing means-actuated bythe tube; i

2. A portable rubbing or polishing machine having, in combination, a tubular body, a ltube slidably mounted within the body, said tube having closed ends, a tubular elementA located within said'tube and secured to the body, valve parts in the .ends of 'said tubular element, coperating valve parts eX- tendin'g through said tubular element and secured to the tube, means for supplying pressure iuid to the interior of said tubular element, andv a rubbing element secured to 3. A portable rubbing'v or polishing machine having, in combination,l a body, atube slidably supported by the body, said tube lhaving closed ends, a tubular `element. llo-.-v ncated within said tube. and secured to the body,valve parts inthe ends of said tubular ports which are arranged to be covered by los' said tubular element, and a rubbingelement 'p secured to said tube.

. :4. A portable rubbing or polishing machine having, in combination, va tubular body, two cylinders slidably mounted within the body, the ends of said element constitnting pistons which are opposed to the-cylinder heads, means for admitting pressureff fluid to the interior of the tubular element, the handle and having heads, jatubular element wlthin said .cylinders andv secured tok -means for controlling l thenow. of pressurel v1i iuid to and from the cylinders, and rubbing means actuated fby said .cylinders'.

. 41'20.A 'i A5. A `portable rubbing or. polishing ma- Lchine having, in combination, -a-'tubular' body, two vcylinders rigidly secured together andslidably mounted withinethe body and. vhaving heads, a tubular element withi'nlsaid .cylinders and securedto'thebody, the ends of said element constituting. pistonswhich are opposed to the cylinder-heads, means for admlttmg pressure Huid to the .interior ofl the tubular element, means for controlling the iow of pressure iuid to and from the cylinders, and rubbing means actuated by said cylinders.

6. A portable rubbing or polishing machine having, in combination, a tubular body, two cylinders rigidly secured together and slidably mounted within the body, a tubular element within said cylinders and secured to the body, the ends of said element constituting pistons, means for admitting pressure Huid to the interior of the" tubular element, a valve member connected to the cylinders and extending through the tubular element, coperating valve members in the tubular element, said cylinders having exhaust ports which are arranged to be closed by the tubular element, and rubbing means actuated by said cylinders.

7. A portable rubbing or polishing machine having, in combination, a tubular body, two cylinders rigidly secured together and slidably mounted within the body, a tubular element within said cylinders and secured to the body, the ends of said element constitutingpistons, means for admitting pressure iiuid to. the interior of the tubular element, a valve member connected to the cylinders and extending through the tubular element, valve members in the tubular element, said cylinders having exhaust means, and rubbing means actuated by said cylinders.

8. A portable rubbing or polishing machine having, in combination, a tubular body, two cylinders rigidly secured together and slidably mounted within the body, a tubular element within said cylinders and secured to the body, the ends of said element constituting pistons, means for admitting pressure fluid to the interior of the tubular element, a rod extending from end to end of the cylinders and axially through the tubular element, the rod being fixed to the cylinders, valve members for the end portions of the tubular element, coperating valve parts on the rod, said cylinders having exhaust means, and rubbing means actuated by said cylinders.

9. A portable rubbimg or polishing machine having, in combination, a tubular body, two cylinders rigidly secured together and slidably mounted within the body, a tubular element within said cylinders and secured to the body, the ends of said element constituting pistons, means for admitting pressure uid to the interior of the tubular element, a rod extending from end to end of the cylinders and axially through the tubular element, said rod being fixed to the cylinders, valve members for the end` portions of the tubular element, coperating valve parts on the rod, said cylinders having exhaust ports which are arranged to be closed by the tubular element, and rubbing means actuated by said cylinders."

10. A portable rubbing or polishing machine having, in combination, a body, two cylinders rigidly secured together and slidably supported by the body, a tubular element within said cylinders and secured to the body, the ends of said element constituting pistons, means for admitting pressure fluid to the interior of the tubular element, means for controlling the flow of pressure fluid to and from the cylinders, and rubbing means actuated by said cylinders.

11. A portable rubbing or polishing machine having, in combination, a body, two reciprocatory cylinders supported by the body, heads secured to the remote ends of said cylinders, pistons in said cylinders supported by the body, valve means for said cylinders, and a rubbing-element attached to the cylinders.

12. A rubbing or polishing machine having, in combination, a pair of cylinders rigidly connected together, a pair of pistons for the cylinders, said pistons being rigidly connected together, means to'prevent relative turning movement between said pairs of elements, one of said pairs of elements having a central chamber provided with alined ports communicating with the cylinders, a rod fixed to the other pair of elements and extending into said chamber, said rod having portions constituting valves that control the i'low of pressure iuid through said ports to the cylinders, and rubbing means actuated by one of said pairs of elements.

13.' A portable rubbing or polishing ma- 4vchine having, in combination, a body, a pair of cylinders rigidly connected together, a pair of pistons for the cylinders, said pistons being rigidly connected together, pressure-iiuid-controlling means for the cylinders, a handle secured to the body and to one of said pairs of elements, and a rubbing element rigidly attached to the other of said pairs of elements.

14,-. A portable rubbing or polishing machine having, in combination, two reciprocatory cylinders rigidly secured together, a piston-forming element in said cylinders, valve means in said element, coperating valve means attached to said cylinders, means for admitting pressure Huid to the interior of said element, and rubbing means actuated by said cylinders.

15. A portable rubbing or polishing machine having, in combination, a body, two reciprocatory cylinders rigidly secured together, a piston-forming element in said cylinders secured Vto said body, valve means in said element, coperating valve means at'- tached to said cylinders, and rubbing means actuated by said cylinders.

16. A portable rubbing or polishing machine having, in combination, two reciprocatory cylinders rigidly secured together, a

I valve means in said element, cooperating valve means attached to said cylinders,

means for admitting pressure vi'iuid to theinterior of said element, and a rubbing. element rigidly attached to saidv cylinders.

17. A portable rubbing or polishing machine having, in combination, a body, 'tw-o v inders'rigidly connected together, a pair of reciprocatory cylinders rigidly secured t0- gether, means to prevent relative rotation between the body and the cylinders, pistons in said cylinders rigidly secured to said body,"

a handle secured to the body, said handle having a fluid sup ly passage communicating with the space between the pistons, valve means for said cylinders, and rubbing means actuatedby said cylinders. v

18. A portable rubbing or polishing machine having, in lcombination, a body, two

reciprocatory cylinders rigidly secured togethe'r, a piston-forming element in saidlcylinders secured to saidl body, a handle secured tol the body, said handle having va .fluid `supply 'passage communicating with the interior of' said element, valve means in 4said element, coperating valve means attached to said cylinders, and rubbing means actuated by said cylinders.

rigidly connected together, a pair of tons for. the cylinders, said pistons bemg rigidly connected together, means to pre- 85 vent relative turning movement between '19. rubbing or poli hing machine having, in combination, a pair of cylinders said pairs of elements, one of said pairs of elements having a central chamber, a -rod fixed to the other air of elements and extending into said c amber, said rod having portions constituting valves that control the flow of pressure fluid from said chamber to the. cylinders, `and rubbing means actuated by one of said pairs of elements.

20. A'portable rubbing or polishing machine having, in combination, a pair of cylpistons for the cylinders, said pistons being rigidly connected together and having a central chamber, means to prevent relative turning movement between said pairs of elements, means for admitting pressure fluid to the central chamber, means for controlling the flow ofpressure fluid from said chamber to the cylinders, and a rubbing element rigidly attached to one of said pairs of elements.

21. A rubbing or polishing machine having, inl combination, a pair. of cylinders yrigidly connected together, a pair of pistons for thecylinders, said ,pistons being rigidly connected together, means to prevent relative turning movement between said pairs of V elements, one of` said pairs of elements having a central chamber with means for admitting pressure fluid to said chamber, means controlling the flow of pressure fluid .from said chamber to the cylinders, and rubbing means actuated by one of said pairs of elements.

ln testimony whereof, I have hereunto set my hand.

GUSTAF H. EKSTROM. 

